Goofs

When Splinter catches a knife that was thrown at him, the film is edited so his hands are shown letting go of the Nunchaku he was holding only after he catches the knife.

When Danny exits the sewer via the manhole cover, he slides it up and to the left. When the scene cuts to Casey Jones and then Casey Jones walking passed the manhole cover, it is noticeably down and to the left.

April O'Neil's answering machine still works despite the power to her apartment being cut by The Foot Clan.

When Raphael is looking at the traffic from the top of April's building right before the foot come at him, the building looks like it has at least 15-20 stories. When Danny is looking at the building burning it has only 2 stories.

During the apartment fight, the electricity gets severed. But a few minutes later, April's boss calls to say she's fired.

The turtles' shells are flexible and made of soft material throughout. This is visible when they touch something, as well as when the actors move their arms or bodies drastically (they bend with their bodies). Real turtle shells, including teenage mutant ninja turtle shells throughout the stories, should be hard and inflexible.

Shortly after the pizza is delivered through the sewer grating, Donatello is seen with a napkin tucked under his chin. How can he do that if he isn't wearing a shirt to tuck it into?

The Teenage Mutant Ninja Turtles live in the sewer of Manhattan (in New York City). Sewers handle the bodily waste of several million people. There is no possible way that the Turtles could completely avoid coming in contact with human waste while moving through the sewer tunnels.

In the background of one of the shots of the city, there is a clear poster for "Critters" hanging on a wall outside a theatre, despite it being made four years earlier (1986). However, the theatre could be showing a revival screening of the film.

As Leonardo leaves April's apartment, we see his sword bend against the wall, like rubber.

When the Foot clan bring out the axes to fight with in April's apartment, the floor already looks like it's been hacked into before the first ax touches the ground.

While fleeing the Foot Clan in the junk shop, the same brief scene of Donatello turning and punching out one of the Foot is used twice.

Several times throughout the movie, the turtles' weapon belts squeeze their breast/stomach-plates in, suggesting they might be made of a soft material, like foam.

At the beginning of the "This is What we Do" sequence, when the camera is focused on the cigar-smoking boy playing pool, the Bubblegum Girl from the very next shot can be seen waiting around on her mark in the background.

Endorsement backfire: Because the turtles have long been devotees of pizza, Pizza Hut was one of the main endorsers of the movie, creating and distributing much of the Turtles' merchandising before the movie's premiere. However, all the deliveries in the movie were shown to be from Domino's.

When first attacking Shredder, Leonardo jumps headlong into the air with his swords out, which leaves him very easy to parry by Shredder's spear. No skilled martial artist would ever attack someone in such a clumsy and reckless manner. Shredder himself makes a similar blunder shortly afterwards by running full-throttle towards Splinter with his spear out.

In April's apartment, after the turtles watch April's interview on TV in which she thanks Raphael for saving her, Donatello says that Raphael is turning red from embarrassment, but Raphael actually responds in Leonardo's voice, not his own.

During the final fight, a foot soldier is thrown into the staircase of a fire escape. He grabs his head in pain and we hear the clanging sound, but we see that his head never even got within a foot of the metal.

In the beginning, when the Turtles are shouting various phrases after their first battle, Donatello yells, off-screen, "Bossa nova!" but on-screen Leonardo's lips move.

Several times throughout the film, Donatello uses Raphael's voice instead of using his own, like when he is punched or kicked by a Foot Clan member.

Michelangelo screams Splinter's name while standing on top of the barn, but does it in Raphael's voice. (Look closer for the nunchuks on his belt as proof that it's actually Mikey.)

When Raph and Leo are arguing in April's apartment, there is a crew member with an orange baseball hat on trying to hide under the table.

After Raphael wakes up in the bathtub, Donatello laughs at a joke. As he does so he tilts his head back and opens his mouth, revealing the face of the actor underneath the costume.

At the end of the movie, when Shredder is running towards Splinter with the staff, part of the sound stage is visible (on the full screen version).

When Donatello is skateboarding in the sewers to meet with Michelangelo while Mikey is waiting for the pizza, you can see, for a couple of frames, a human hand (which should be Donny's) move in and then out of the camera viewpoint while he is doing a spin.

When Michelangelo yells as he's fighting on the street in the last scene, you can see the actor through the mouth opening.

When Raphael gets attacked by the Foot soldiers on April's roof, one of them tosses both of his sai over the edge of the building. Yet later in the movie, he has the weapons back even though he never had a chance to find and recover them.

It's never been explained how the Turtles get money to buy pizzas and go to the movies.

When Raphael goes to the movies, he makes every effort to disguise himself, but it's not very likely the ticket-taker wouldn't have noticed he was a giant mutant turtle.

When Casey Jones first comes to help the turtles again the foot clan in April's apartment, wearing a hockey mask, Donatello asks "who's that?" Michelangelo answers "Wayne Gretzky? On steroids?" Gretzky played as a centre and was never a goaltender in his NHL career.